I am fresher on this site as well to "quality ".
I need to know "how to go on this ladder ? means
From where should I start my studies, the things to know & is it more therotical based study / practical based from interview point of view ?
You have made the right decision to pursue a career in Software Quality !
It's always better to start with the theoretical knowledge and move towards the practical applicability of it. You got to get acquaintance with the people associated with Quality activites of an organization, attend meetings of different Quality forums in your city and then share knowledge...that's the best way I could think of, to learn all about Quality.
Believe me, it's the most interesting field to work with, ofcourse, if you've the spirit to pursue it.
Congratulations and All the best !